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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

19549 results found.

  1. GRB 050525: MITSuME Optical Observation in VRI
  2. GRB050525A,optical observation
  3. GRB050525: Super-LOTIS observations
  4. GRB050306: optical afterglow not confirmed
  5. GRB 050525: BART optical observation
  6. GRB 050525A: BOOTES simultaneous optical observations
  7. GRB050525: Optical observations
  8. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  9. GRB 050525: TAROT observations of the early afterglow
  10. INTEGRAL detection of GRB 050525
  11. GRB 050525, infrared observations
  12. GRB 050525: Optical observation
  13. GRB 050525: observatons of the optical afterglow
  14. GRB050525: ROTSE-III Refined Analysis
  15. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  16. XRF050522: Radio Observations
  17. Swift/UVOT observation of XRF 050522
  18. GRB 050509A: Further I-band imaging
  19. GRB050522,optical observation
  20. GRB050520,optical observation
  21. XRF 050522: Continued NIR P200 Monitoring
  22. RBO Observations of GRB050522
  23. Recent GRB BVRcIc field photometry
  24. GRB050520: Radio Observations
  25. XRF 050522: Swift XRT observation
  26. XRF050522, BVRcIc field photometry
  27. XRF050522: Optical Observations
  28. XRF050522: Near-infrared Observations
  29. GRB 050520: VLT/ULTRACAM observations
  30. Swift UVOT Observations of GRB 050520
  31. XRF050509c: Radio Observations
  32. RBO Observations of GRB050520
  33. GRB 050520: P200 Observations
  34. GRB050520: Liverpool Telescope follow-up
  35. RBO Observations of GRB050520
  36. GRB 050520: TAROT optical limit
  37. GRB 050520: VLT/ULTRACAM observations
  38. GRB050502b: Early Observation
  39. GRB050509b, Bok telescope B-band imaging
  40. GRB050509b, SDSS pre-burst observations
  41. GRB 050509b: Keck/Chandra Cross-Correlation
  42. GRB 050509b: Keck/Chandra Cross-Correlation
  43. Chandra observation of GRB 050509b
  44. GRB 050509b Milagro GeV/TeV Observations
  45. GRB050509B: Optical observations at the Very Large Telescope
  46. GRB 050509b: No Optical Variability in XRT Error Circle
  47. GRB 050509c: ROTSE-III Optical Limits
  48. GRB 050505, early TAROT observation
  49. GRB050509c: REM NIR and Optical observations
  50. GRB 050505: SARA Observations
  51. GRB 050509B: Swift/XRT refined analysis
  52. GRB 050509A: Optical observations
  53. GRB050509b: Radio Observations
  54. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  55. Swift Detection of GRB050509b: A short duration burst
  56. Swift Detection of the Burst GRB050509
  57. GRB 050505, simultaneous optical observation
  58. GRB050505: AAVSO observations
  59. GRB050416A : 1 GHz limit from GMRT
  60. GRB050505: Optical Afterglow Candidate
  61. GRB 050416b:Swift XRT afterglow upper limits
  62. GRB 050416b:Swift XRT afterglow upper limits
  63. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  64. GRB050502b: Afterglow Confirmation
  65. GRB050502: P200 Observations (Correction)
  66. GRB050502: P200 Observations
  67. Swift UVOT observation of GRB 050504
  68. GRB050504: P60 Observations
  69. GRB 050504: A long GRB detected with INTEGRAL
  70. GRB (?) 050504: IR Observations, Intriguing Source
  71. GRB 050502b, Optical observations
  72. GRB050502a: P60 Observations (Correction)
  73. GRB050502a: P60 Observations
  74. GRB050502B Swift-BAT refined analysis
  75. Swift Detection of the Bright Burst GRB050502b
  76. GRB 050502: ROTSE-III Detection of Possible Counterpart
  77. Swift/BAT possible detection of a weak burst GRB050430
  78. GRB050416a: Radio Detection
  79. Swift Detection of GRB 050422
  80. GRB 050421: SLOTIS observations
  81. GRB 050421: Further Analysis of IR imaging
  82. GRB050421: Radio Observations
  83. GRB050421: Radio Observations
  84. GRB 050421: IR Observations
  85. GRB050421
  86. GRB 050421: NIR observations
  87. GRB050421: P60 Observations
  88. GRB 050421: BOOTES-2 simultaneous optical observations
  89. GRB 050416b: Tentative Swift XRT Position
  90. GRB 050315: potential host galaxy
  91. GRB050326: analysis of the XMM-Newton observation
  92. GRB050418: Null Optical Observations
  93. GRB050416A, optical observations
  94. GRB 050418: Swift-BAT refined analysis
  95. GRB 050416: Mitsume optical observation
  96. GRB050416B: IR observations
  97. GRB050412: Radio Observations
  98. GRB 050416: Swift/UVOT detection of afterglow emission
  99. GRB 050416,optical observation
  100. GRB050416: P200 NIR Observations

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